Permanent molding apparatus



eh 4, 1936. R. J. Rosi-MRT ET AL 029973 -PERMANENT MOLDNG APPARATUSFiled Aug. 15, 1952 e sheets-sheet l ,i will) @w Mgg/MM Feb. 4, 1936. R.J. Rosi-HRT ET AL ZQWE ?ERMNENT MOLDING APPARATUS Filed Aug. 15, 1952 f6 Sheets-Sheet 2 Fell 4, 1935:- R. J. Rosi-HRT ET AL 2,029,673

PERMANENT MOLDING APPARATUS Filed Aug. 15, 1952 e Sheets-sheet 5 Feb. 4,1936. R. J. Rosi-HRT Er AL PERMANENT MOLDING APPARATUS Filed Aug. 15,1932 6 Sheets-Sheet 4' Sme/WMS' Feb. 4, 1936. R J, RQSHIRT Er AL2,029,673

PERMANENT HOLDING' APPARATUS Filed Aug. 15, .1932 6 Sheets-,Sheet 5 m'Myww- Fb. 4, 193e. R. J. ROSHIRT EN. 2,029,673

, PERMANENT MOLDING APPARATUS Filed Aug. 15, 1932 6 Sheets-Sheet 6invention may be advantageously employed in.

Patented Feb. d? i935@ PATENT OFFICE PERMANENT MOLDING APPARATUSRandolph J. Roshirt, Arthur T. Bateman, and Andrew Irvine, Detroit,Mich., assgnors to Bohn Aluminum and Brass Corporation, Detroit, Mich.,a corporation of Michigan Application August 15,1932, Serial No. 628,946

10 Claims. (Cl. .Z2-136) This invention relates generally to moldingequipment and refers more particularly to permarient molding apparatus.

While the inventive principles of the molding apparatus forming thesubject matter of this connection with different types of moldingequipment for forming castings of various shapes, nevertheless, theseprinciples render it practical to fashion an internal combustion enginecylinder head casting from apermanent mold, and, accordingly, findparticular utility when employed for this purpose.

The desirability of permanent molding apparatus for production use overthe ordinary sand mold process is well recognized in that the former notonly simplifies, renders more efiicient and reduces the cost of molding,but provides for obtaining a more accurate casting. Furthermore, it hasbeen found that the formation of a casting from a permanent moldmaterially increases the density of the casting which is especiallyadvantageous when the latter is formed from aluminum or some metalhaving similar characteristics. Notwithstanding the foregoingindisputable advantages of permanent molding, a large number ofmanufacturers still resort to sand molds for the commercial productionof internal combustion engine cylinder head castings. The unpcpularityof permanent molding apparatus in the production of cylinder headcastings is attributed to the complicated nature of the latter and tothe diiculty heretofore encountered in designing a commerciallysatisfactory apparatus capable of forming castings accurately andexpediently.

The present invention contemplates the provision of permanent moldingapparatus composed of a few, simple parts movable relative to each otherin accordance with a predetermined sequence and having portionscooperating with each other in one relative position thereof to form a.permanent mold cavity conforming exactly in cont-our to the shape oi thecasting. vMovement of the aforesaid parts to their various positions ofadjustment is accomplished automatically in timed relation to cachother, and the use of sand in any ferm is -obviated with the result thatthe formation of the mold is materially expedited.

A further object of this invention which contributes materially to thecommercial acceptability of the castings formed thereby is attributed tothe cooperation of a number of features of the apparatus to form acasting free from porosity and Within limits heretofore consideredimpossible. In forming cylinder head castings in production, accuracy inmolding is extremely desirable since variations in the dimensions of thecombustion chambers produces corresponding variations in the volumetriceiiiciency of the cylinders, and, accordingly, detrimentally affectsengine performance.

One of the features of the present invention consists in the provisionof permanent molding apparatus fashioned to minimize obstructions in themold cavity tending to interrupt the flow of metal and produce agitationwhich is responsible to a large extent for blowholes in the casting.Elimination of blowholes in a cylinder head casting is especiallydesirable owing to the high pressures obtained and the necessity forcertain types" of heads to retain a cooling medium.

Another feature of the permanent molding apparatus forming the subjectmatter of this invention is attributed to the novel means provided formaintaining the metal in the feeding portions or risers of the mold at asuiiiciently high temperature to insure a satisfactory ow of the metalinto the mold cavity. By reason of the foregoing, the volumetriccapacity of the risers may be reduced to the minimumwithout affectingthe supply of metal tothe mold with the result that a material saving inmetal is realized.

While the foregoing features are advantageous irrespective of the metalemployed in forming the mold, nevertheless, they are especiallydesirable whenthe castings are fashioned from aluminum or some metalhaving similar characteristics due to the fact that these metals-usuallyhave a comparatively low pouring temperature and for this reason freezeor solidify at a relatively high rate. Consequently, in forming castingsfrom metals of the above type, it is especially important that the metalbe maintained at the desirable temperature and that the flow of metal inthe mold cavities be continuous and uninterrupted. Inasmuch as thepermanent molding apparatus illustrated herein provides for obtainingthe foregoing results as previously stated, it will be apparent that thesame is particularly applicable to forming cylinder head castings frommetals having high thermal conductivity such as aluminum.

A further advantageous feature of the present invention resides in thenovel gating-means employed in the permanent mold which, together withthe above features, insures the provision of an efficient casting.

The permanent molding apparatus forming the subject matter of thisinvention possesses numerous other structural features which areextremely Figure 2 is a plan view of the lower section l aforesaid ofthe head;

Figure 3 is a bottom plan view of the section shown in Figure 2;

Figure 4 is a transverse sectional view taken substantially on the line4 4 of Figure 1;

Figure 5 is a plan view of the molding apparatus constructed inaccordance with this invention and showing the several relativelymovable parts in positions wherein the mold is closed;

Figure 6 is a fragmentary cross sectional view through the several moldparts taken substantialiy on the line 6-6 of Figure 5;

Fes

Figure 7 is a perspective view of the molding apparatus showing theseveral parts thereof in positions wherein the mold is opened;

Figure 8 is a cross sectional view through the several parts of themolding apparatus showing the latter in another position of adjustmentand taken substantially on the line 3 8 of Figure 5;

Figure 9 is a fragmentary cross sectional View illustrating the mannerin which the casting is ejected from one of the permanent mold sectionsand taken substantially on the line 8 9 of Figure 5;

Figure l0 is a side elevational view of the molding apparatus;

Figure 11 is an inner side elevational view of one of the permanent moldsections;

Figure 12 is an inner side elevational view of a cooperating permanentmold section;

Figure 13 is an enlarged cross sectional View' through a pair ofcooperating permanent mold sections illustrating the riser construction.

Owing to the extremely satisfactory results obtained in molding internalcombustion engine cylinder heads from aluminum by our improved permanentmolding apparatus, we have shown the latter herein for the purpose ofillustration as employed in the manufacture of aluminum cylinder headcastings.

'I'he molding apparatus to be presently described may be more clearlyunderstood by first referring to the particular construction of cylinderhead adapted to be cast by the apparatus. As shown in Figures 1 to 4,inclusive, the cylinder head is preferably of the water cooled type .andcomprises two separable sections 20 and 2| arranged in superposedrelationship in the assembled position of the head. The lower section 2|of the head is formed with a plurality of combustion chambers 22 in thelower face thereof, and in the present instance, is preferablyfashioned' from a metal having a high thermal conductivity s'uch asaluminum or an aluminum alloy. The section 2| is open at the upper sidethereof and is lprovided with upwardly extending side walls 23integrally connected with the stud bosses 2l which are apertured as at25 for the passage of suitable studs 26.4 The top wall portions of thecombustion chambers 22 as well as the entire section 2| is reinforced byribs-21 integrally connecting the aforesaid wall portions ,to the sidewalls 23 of the section 2|. The latter, in addition to having theopenings 25 through the bosses 24 for the studs, is further providedwith openings 28 therethrough arranged to permit the circulation of acooling medium through the head.

The upper section 20 serves to close the open side aforesaid of thesection 2| and is preferably formed of cast iron or some material havinga relatively high tensile strength so as to reinforce the aluminumsection 2| when clamped thereto by means-of the studs 26. In detail, thesection 20 is provided with marginal side walls 29 extending downwardlyfrom the top thereof and fashioned to seat or abut the upper edges ofthe side walls 23 on the lower section 2|. The top wall of the uppersection 20 is also provided with stud bosses 30 extending downwardlytherefrom for seating engagement with the stud bosses 24 on the lowersection and having openings 3| therethrough registering with theopenings 25 to permit free passage of the studs through both sections.The upper section 20 is also provided with a plurality of depressions 32corresponding in number to the number of combustion chambers and havingopenings 33 therethrough in registration with openings 34 in the topwalls of the combustion chambers to accommodate the` usual spark plugs.The bottom surfaces of the depressions 32 are fashioned for seatingengagement with the portions of the top walls of the combustion chamberssurrounding the spark plug openings 3| therethrough so that when thesection 2| is clamped between the section 20 and the cylinder block (notshown), the aforesaid depressions will serve as an effectivereinforcement for the combustion chambers.

The section 20, in addition to forming a structural reinforcement forthe section 2|, also cooperates therewith to form-a water space abovethe combustion chambers, and\permits eliminating lthe complicated waterjackets usually employed in a cylinder head of the one-piece type. Theelimination of the conventional type of water jacket is an importantfeature since it materially simplifies the manufacture of both sectionsfrom a permanent mold. It will further be observed that the abovecylinder head provides for obtaining all of the recognized advantagesresulting from the formation of the combustion chambers of a metal ofrelatively high thermal conductivity and at the same time possesses thenecessary rigidity. y

While it has been stated that both sections of the composite headpreviously described may be formed from a permanent mold, nevertheless,the apparatus specifically shown herein is particularly designed for thepurpose of molding the lower cylinder head casting 2|. We haveillustrated the invention in this `manner not only because the permanentmolding apparatus shown herein is particularly applicable to formingaluminum castings, but also because it is capable of forming a castingto accurate predetermined limits which is desirable in manufacturing thecylinder head casting 2|. With our permanent melding apparatus about Atobe described, the combustion chambers are all of accurate predeterminedsize with the result that the volumetric eiiiciency of the chambers isuniform and the performance of the engine thereby materially increased.

The permanent molding apparatus for forming the casting 2| comprises ingeneral three relatively movable sections cooperating with each other inthe relative positions thereof shown in Figure 6 to form a mold cavitycorresponding in contour to the shape of the casting 2|. The threesections referred to above are designated herein by the referencecharacters 40, 4| and 42 and are operatively connected for actuation inaccordance with a predetermined sequence. Assuming that the sections arein positions wherein the mold is open as shown in Figure 'I and that itis desired to closethe mold. the section 42 is moved relative to theremaining sections in a direction toward the section 4| to extend thepermanent core members carried thereby in operative relationship to thesection 4|. Both the section 42 and the section 4| are then caused tomove as a unit toward the section 40 and power is applied to the latterfor moving the same in a direction toward the aforesaid sections incooperative relationship thereto. Upon completion of theY foregoingoperation, a mold cavity is formed by the sections which correspondsexactly in contour to the shape of the casting 2|.

Assuming now that itis desired to open the mold, the section 42 is movedrelative to the other sections in a direction away from the section 4|in order to withdraw the permanet cores carried thereby from the castingwhile the latter is supported between the sections 4|)` and 4|.

As soon as the core members are withdrawn from the casting, the section4| is caused to move as a unit with the section 42 in a correspondingdirection away from the section 40. As will be more fully hereinafterset forth, the casting is clamped at a plurality of spaced points to thesection-404 during relative movement of the section 4| away from theformer section with the result that the 'casting will be effectivelystripped fromthe lat- 'ter' section and deformation thereof prevented.

The section 49 is then moved in a direction away from the section 4| andduring this movement. the casting is ejected therefrom by suitable meanswhich will also be made more apparent as'this description proceeds.

Referring now more in detail to the permanent molding apparatus brieflyoutlined above, it will be noted that the same comprises a table 44having upright members 45 and 48 fixed to the top surface thereof inspaced relation to each other. Slldably supported by the table 44between the uprights are the sections 4|! and 4|. Both of the aforesaidsections are formed with recesses 41 and 48 in the adjacent verticalfaces thereof adapted to register with each other in the innermost orclosed positions of the sections.

'Secured within both the recesses 41 and 48 are suitable inserts whichare accurately formed to cooperate with each other in the closedpositions of the mold sections to form with the mold parts carried bythe section 42 a mold cavity corresponding exactly to the shape of thecylinder head casting 2i.

In detail, the recess 41 in the permanent mold section 40 is fashionedto receive a plurality of inserts 49 having core portions 59 formedintegral therewith and fashioned to project beyond the inner verticalface of the mold section 40. The core portions 5d are accuratelymachined to correspond to the combustion chambers 22 in the casting 2land in the present instance, two core members are formed on each insert49. The spark plug openings 34 through the upper wall of the combustionchamber 22 in the cylinder head casting 2i are formed by permanent coremembers 5| sleeved within openings in the inserts 49 and having theouter ends projecting beyond the permanent core 50 a suicient distanceto form the aforesaid openings 34. Although the permanent cores 5i maybe formed integral with the inserts if. desired, nevertheless, we preferthe construction shown herein since it provides for more satisfactorilyventing the mold. other words, the clearance between the side walls ofthe core members 50 and openings in the inserts through which the sameextend permits the gas occulted in the metal to escape with the resultthat porosity is minimized.

In addition to the above core members, the inserts 49 are provided withpermanent core members 52 having portions extending outwardly beyond thevertical face of the mold section 4i! a suilicient distance -to form theopenings provided ln the casting 2| for the passage of water or othercooling medium. The core members 52 vary in shape as will be observedfrom Figure 12 and are assembled with the inserts in the same manner asthe permanent cores 5| so as to facilitate venting of the mold. In theevent the casting is provided with an opening therethrough for l thepassage of the distributor or accessory shaft of the engine, one of theinserts 49 may be provided with an additional permanent core 53 securedto the insert in the samel manner as the cores 5| and having. a portionprojecting beyond the inner face of the mold section 4|) a sumcientdistance to form the desired opening.

'I'he recess 48 in the permanent mold section 4| is fashioned to receivea plurality of inserts 54 corresponding in number to the4 number ofinserts 49 and having recesses 55 in the outer faces thereof registrablewith the permanent cores 50 on the inserts 49 to form therewith a moldcavity corresponding exactly to the walls of the combustion chambers 22in the casting 2|. The inmembers on the inserts 49 to form the desiredcavity in the casting 2|, and in addition are provided with openings 5Stherethroughfor the passage of the mold parts carried by the section 42into the mold cavity. It will be observed from the foregoing that thecasting is formed in the permanent mold section 4| and the section 40merely carries a number of the cores for imparting the desired contoursto the casting.

While it will be understood from the previous description that thecooperating inserts may be formed integral with the adjacent verticalfaces of the mold sections 4U and 4|, nevertheless, several distinctadvantages are secured by forming the same of a plurality of membersseparate from the mold sections 40 and 4|. By resorting to the presentconstruction, the gas occulted in vthe molten metal is not onlypermitted to escape mold sections 40 and 4| of the apparatus.Furthermore, the present arrangement provides for adjusting the insertsrelative to each other so as to compensate for any slight variations inthe construction. may be interposed between adjacent walls of theinserts and mold sections so that by properly selecting the shims, thedimensions of the mold cavities formed by the inserts may be accurately'controlled.

As indicated above, the mold section 42 is also slidably mounted uponthe table 44 and carries a plurality of mold parts adapted to cooperatewith the sections 40 and 4| in the position thereof shown in Figure 6 toform a mold cavity conforming in contour to the shape of the casting.

inv

In other Words, suitable shimsv .35 serts 64 also cooperate with theother of the core coy the fonn of core pins 60 extending from thesecbosses 24 on the casting 2|, and the extremities thereof cooperatewith the adjacent portions of the inserts 54 to form the bosses 24 andthe recesses 25 therein. The opposite extremities of the core pinsextend through openings formed in the section 42 and are threaded forreceiving the clamping nuts 63. A pair of the nuts 63 is threaded uponeach core pin for clamping engagement with opposite sides of the section42 in order to adjustably secure the pins thereto.

The core pins 60 are moved as a unit into and out of the mold cavity bymeans of a reciprocable head 64 connected intermediate the ends thereofto a suitable source of power (not shown) and having the ends secured tothe section 42 by the fastener elements designated generally herein bythe reference character 65. The section 42, on the other hand, isconnected to the permanent mold section 4| by means of the studs 66having the inner ends threadedly engaging the mold section 4| as at 61and having the outer ends extending through enlarged openings 68 formedin the opposite ends of the section 42. 'I'hreaded on the outer endportions of each of the studs on opposite sides oi.' the section 42 is apair of adjustable nuts 69 forming axially spaced abutments and normallyheld in accurate spaced re`- lationship by means of lock nuts-1I).v Ingeneral, the arrangement .Fs such as to-provide for actuation of themold section 4| from the reciprocable head 64 in timed relation to theoperation of the latter to move the section 42.. In detail, when thepermanent mold sections are in their separated positions, or, in otherwords, when the mold is openedhthe section 42 is in engagement with theoutermost abutments 69 so that upon initially closing the mold, thesection 42 moves the core pins 60 relative to and toward the moldsection 4| a distance corresponding to the axial space between theabutments 69. The axial distance between the abutments 69 may be readilyvaried due to the threaded engagement of the abutments with the studs,and is so determined as to limit the extension of the core pins into themold cavity. The core pins are shown in their extreme innermostpositions in Figure 6, and as will be observed, terminate short of theadjacent wall of the mold cavity, or, in other words, are prevented fromextending through the casting. In other words, the stud bosses aremerely partially cored by the pins 60, and as will be presently shown,this feature is a decidedly important one.

By merely partially coring the stud bosses in the manner set forthabove, the mold or casting is of substantially constant cross sectionalarea, with the result that localized shrinkage is eliminated. In otherwords, the usual cavity at the upper ends or the stud bosses caused bythe shrinkage of metal in the latter when completely coring the same isobviated and a more eiiicient casting results. Furthermore, with thepresent arrangement, less obstruction is offered to the flow of metalinto the mold cavity, with the result that the tendency of the metal toagitate and produce blowholes in the casting is minimized.

As hereinbefore stated, means is provided upon opening the mold to stripthe casting from the section 4| and to clamp the casting to the section40. The foregoing is accomplished herein by providing bushings 1| on thecore pins. In detail, the bushings 1I are anchored within the stationaryupright 46 and extend inwardly therefrom into the openings formed in thepermanent mold section 4| through which the core pins project. Thelengths of the bushings are so determined that when the permanent moldsections are in their relative positions shown in Figure 6, the innerends of the bushings cooperate to form the portions of the castingencircling the openings through the stud bosses. The outer ends of thebushings 1| are flanged as at 12, or, in other Words, are provided withenlarged head portions adapted to extend within counterbored recessesformed in the inner face of the upright 46 and are secured therein bymeans of a removable plate 13 xed to the aforesaid face of the upright.It will be observed irom Figure 6 that the bushings are loosely securedin place so as to compensate for the differences in expansion of thestationary upright 46 and mold section 4|. The bushings 1| beingstationary with respect to the movable permanent mold section 4|, itwill be noted that the latter may be moved in a direction away from thesection 40 without eecting movement or the casting therebetween. Inother words, the bushings serve to clamp the casting to the section 40during movement of the section 4| in a direction away from the section40 and thereby obviate any tendency for the casting to distort duringopening the mold.

In view of the'fact that the casting is clamped to the permanent moldsection 40 upon opening the mold, we have provided means for ejectingthe casting from this section. The means for accomplishing this resultin the present instance comprises a member 14 similar in generalconstruction to the section 42 of the permanent mold in that it isslidably mounted upon the support and carries a plurality of pins 15which project inwardly therefrom through aligned openings 16 formed in'the section v4|) and inserts carried thereby. The pins 15 are adjustablysecured to the member 14 and are of such length that when the same arein their inoperative positions, the outer ends thereof lie ilush withthe inner vertical face of `the permanent mold section 40.

The ejector carrying plate or member 14 is actuated by a reciprocablehead 11 through the medium of the permanent mold section 40. In detail,the head 11 is connected intermediate its ends to a suitable source ofpower (not shown) and the opposite ends thereof are directly coupled tothe permanent mold section 40 through the medium of suitable connections18 in such a manner that the latter permanent mold section moves as aunit with the reciprocable head 11. The ejector carrying plate 14 isprovided with openings 19 for the passage of the connections 18therethrough, and the latter are equipped with adjustable abutments 80fashioned to engage the outer face of the plate 14. The abutments 80 arefor the purpose of moving the permanent mold section 40 and the ejectorpin carrying plate 14 as a unit in a direction to close the mold, and inaddition serve to position the inner ends of the ejector pins 15 ushwith the inner vertical face of the permanent mold section 40 when themold is closed. rIhe plate 14 is further provided with a pair ofoutwardly extending rods 8| having the outer end portions slidablyengaging openings formed in the stationary upright 45 and having anabutment 82 adjustably secured thereto in a position to engage the innerface of the upright for arresting movement of the plate 14 prior tocomplete retraction of the permanent mold section 40; In detail,movement of the permanent mold section 40 in a direction away from itscooperating section 4| will effect a corresponding movement of the plate14 owing to the fact that the inner ends of the ejector pins are inengagement with the casting. The section 40 and plate 14 are retractedas a unit until the abutments 82 engage the xed upright 45 whereuponcontinued retraction of the section 40 causes the lejector pins 16 toproject beyond the inner vertical face of the section 40, and in sodoing ejects the casting from this latter s ection. As will be observedfrom Figure 5. the abutments 82 maybe assisted invtheir action by meansof additional abutments 85 in the form of stud bolts having threadedshanks anchored within the plate 14.

Operationl Assuming that the several relatively movable parts of themolding apparatus described above are in the positions thereof shown inFigure '1 and that it is desired to form a casting, power is applied tothe head 64 to move the same in an inward direction. Owing to the directconnection between the head 64 and core pin carrying section 42, thelatter is moved as a unit with the head 64 in a corresponding direction.Due to the lost motion connection between the section 42 and permanentmold section 4|, the section 42 is moved relative to the permanent moldsection 4| until the former strikes the innermost abutments 69 at whichtime the core pins are in their proper relationship with respect to thepermanent mold section 4| As previously stated, the abutments arecarried by members ilxed relative to the section 4| so that continuedmovement of the section 42 by the head 64 will causev a correspondingmovement of the permanent mold section 4| relative tothe stationary corepin bushings 1|. When the above cycle of operation of the apparatus iscompleted. the aforesaid relatively movable parts thereof assume thepositions shown in Figure 6 and require no further attention on the partof the operator.

During movement of the aforesaid sections to their operative positionsshown in this latter figure, or after the same have been moved to theseI positions, the permanent mold section 40 is moved into cooperativerelationship with the section 4|. 'I'his is accomplished by applyingpower to the head 11 in such a manner as to move the latter inwardly,.and since the same is directly connected to the permanent mold section40, the

latter will be moved as a unit therewith in a corresponding direction.Inasmuch as the aforesaid connections between the permanent mold section4|lwand head 11 are provided with abutments adapted to engage the outerface of the ejector carrying plate 14 in the manner specified above, thelatter will be moved with the section 40 to the positions thereof shownin Figure 6. Accurate registration of the inserts carried'by theadjacent vertical faces of the two cooperating permanent mold sectionsis insured by means of guide members 86 fixed to opposite ends of one ofthe sections and adapted to register with recesses 81 formed in thecorresponding ends of the cooperating mold section. After all of therelatively movable mold parts are in their assembled relationship asshown in Figure 6, the two cooperating sections 40 .and 4| are clampedtogether by means of suitable clamps 88 pivotally mounted in pairs onopposite ends of one of the sections for engaging cooperating parts 89on the corresponding ends of the adjacent section. After the clamps havebeen operated to positively secure the sections 40 and 4| together, themolten metal may be poured into the mold in the manner to be more fullyhereinafter set forth. v

Assuming now that the mold has been poured and that it is desired toopen the same, power is applied to the head 64 causing the latter,together with the section 42, to move outwardly relative to thepermanent mold section 4| until, the section 42 engages the outermostabutments 1 supported by both the sections 40 and 4|, the

core pins are withdrawn therefrom. After the core pins are withdrawnfrom the mold, continued outward movement of the section 42 causes acorresponding outward movement of the mold-section 4| through theoutermost abutments 69 in the manner set forth above. aforesaid outwardmovement of the section 4| is effected relative to the stationarybushings 1| surrounding each of the core pins and engaging the castingwith the result that deformation of the castingis prevented since eachof the bushings serves to maintain the casting in supportingrelationship to the permanent mold section 40.

Upon completion of the foregoing operations, power is applied to thehead 11 causing the latter to move outwardly and effecting acorresponding movement of the mold section 4|) through the medium of theconnections 18 between` the mold section 4|) and head 11. While movementof the section 40 in the above direction destroys the supportingrelationship between the bushings 1| and casting, nevertheless,

` the latter adheres to the core members or inserts upon the section 40,and, accordingly, is

carried outwardly therewith. Inasmuch as the inner ends of the ejectorpins are in engagement withdrawing the same from the casting without anytendency of deforming the latter.

It will be observed from the foregoing that wev have provided apparatuscapable of forming a complicated casting and composed of a relativelyfew number of parts cooperating with each other in one position thereofto form a permanent mold cavity conforming exactly in contour to` theshape of the desired casting. It will further be apparent that all ofthe relatively movable parts are automatically operated in timedrelation to each other and while various different sequences ofoperation may be resorted to, nev-` ertheless, we prefer the one setforth above since extremely satisfactory results have been securedthereby.

Much of the commercial value and acceptability of the foregoingpermanent molding apparatus is attributed to the novel means providedfor insuring a continuous even ow of the molten metal into the moldcavity. In general, the molten metal-is poured into gates arranged uponopposite ends of the molding apparatus and communicating with the moldcavity at the bottorn thereof. The metal flows upwardly through the moldcavity into suitable risers arranged above the cavity and communicatingtherewith at the upper end thereof so as to feed back into the same. Indetail,`both the permanent mold sections I0 and 4i are formed withregistering recesses 90 in opposite ends thereof fashioned to cooperatein the closed positions of the sections to form main gates 9| andoverflow gates 92. As shown particularly in Figure 1l, the main gates 9|communicate at the lower ends with a distributing passage 93 extendingbelow the mold cavity for substantially the full length thereof andcommunicating therewith through the lower end thereof as at S4. Thearrangement is such that as the metal is poured within both the gates9|, the same is discharged into the distributing passage 93 and causedto now upwardly through the mold cavity into the risers 95. The risers95 are positioned above the mold cavities in communication therewith andare formed by cooperating recesses in the adjacent faces of the moldsections 40 and Il. It has been found that by supplying the mold cavitywith metal in the manner specified above, agitation of the metal takesplace in the distributing passage 93 before being discharged into themold cavity. This feature, together with the fact that every precautionis taken to prevent agitation of the metal in the mold cavity byminimizing obstruction to the flow of the metal, eliminates any tendencyfor blowholes to form in the casting.

Inasmuch as the metal in the riser above the mold cavity feeds back intothe mold cavity, it is highly desirable that the metal temperature inthe risers be maintained. This is accomplished herein by insulating theside walls of the risers as clearly shown in Figure 13. In detail,

the risers are provided withlaterally spaced side walls 96 and 91 havingsuitable heat insulating material interposed therebetween. 'I'he heatinsulating material minimizes the escape of the heat from the metal inthe riser through the mold sections, and, consequently, maintains themetal in a more liquid state, or, in other words, facilitates the flowof the metal from the risers into the mold cavity. The provision ofmeans of the above type for maintaining the metal temperature isdesirable not only because it cooperates to produce a more eflicientcasting, but also because it minimizes waste since it permits reducingthe volume of the risers to the minimum. The risers may also be`supplied with molten metal directly through the overflow gates ifdesired without interfering with the efficiency of the casting.

It has been found by actual practice that molding apparatus constructedin accordance with the foregoing description not only materiallyexpedites and reduces the cost of manufacture of cylinder head castings,but in addition renders it possible to form the latter from a metalhaving as one of its characteristics high thermal conductivity. Theformation of a cylinder head casting from metals having high thermalconductivity is important since such metals provide for dissipating theheat more rapidly, and, as a consequence, permits compression ratios tobe increasedwithout danger of detonation. While these advantages havebeen recognized by the trade for some time, nevertheless, the commercialproduction of cylinder heads embodying these features was heretoforeconsidered impractical owing to the difficulties encountered in moldingthe same and the expense involved. We have provided herein apparatuswhich renders the commercial production of these heads practical and ata cost considerably lowr than has heretofore been considered possible.

It has also been found that the combustion chambers of cylinder headcastings resulting from the above described apparatus are accuratewithin one cubic centimeter of a predetermined desired volume which isby far more accurate than any molding equipment now commerciallyemployed is capable of producing. Accuracy and uniformity of thecombustion chambers in a cylinder head without the necessity of machin-'ing the latter are highly desirable since these characteristics insureuniform volumetric efficiency of each cylinder of the engine and providefor increasing the performance of the latter.

While in describing this invention the apparatus has been referred to asforming a particular type of cylinder head casting, nevertheless, it isto be understood that the same may be employed advantageously forforming cylinder head castings of various descriptions, and,accordingly, reservation is made to make such changes in the details ofconstruction as may come within the purview of the accompanying claims.

What we claim as our invention is:

1. Permanent molding apparatus for forming a cylinder head castinghaving a plurality of combustion chambers therein, comprising sectionsrelatively movable toward each other and cooperating in their innermostposition to form a permanent mold cavity corresponding in contour to theshape of the casting, means for separating said sections subsequent tothe pouring operation, means engaging one outer face of the casting toclamp the opposite face into engagement with the adjacent mold sectionduring separation of the sections, and means other than last named meansfor subsequently ejecting the casting from the aforesaid section.

2. Permanent molding apparatus for forming a cylinder head castinghaving a plurality of combustion chambers therein, comprisingcooperating sections relatively movable toward each other andcooperating in their innermost posichambers therein and having a seriesof apertured stud bosses, comprising a permanent mold section havingportions upon one face thereof fc.' forming a mold cavity correspondingin contour to the shape of the combustion chambers, a second sectionpositioned adjacent the section aforesaid, means providing for relativemovements of the sections toward and away from each other, a pluralityof core pins fixed to the second section and operable upon relativemovement of the sections toward each other to extend through the firstsection into the mold ca vity for forming the stud bosses in thecasting, and means for ejecting the casting from the'rst sectionincluding sleeves mounted upon said core pins for relative slidingmovement and having the outer ends thereof abutting the portions of thecasting surrounding the core pins.

4'. Molding apparatus for forming a casting of predetermined contour,comprising a permanent mold section having portions on one face thereoffor forming a mold cavity, a section positioned adjacent the sectionaforesaid and having a plurality of permanent -core pins fixed theretoin predetermined spaced relationship, means for relatively moving thesections toward each other to extend the core pins into the mold cavityand for relatively moving the sections away from each other to withdrawthe core pins from the casting, sleeves mounted upon the core pins forrelative sliding movement having the outer ends abuttingthe casting andoperable upon relative movement of the sections away from each other intimed relation to withdrawing the core pins from the casting to ejectthe latter from the first section.

5. Molding apparatus for forming a cylinder head casting having aplurality of combustion chambers therein and having a series of studbosses, comprising a permanent mold section having portions on one facefor forming a mold cavity corresponding in contour to the shape of thecombustion chambers, a second section mounted adjacent the opposite faceof the section aforesaid, a series of core pins corresponding in num-`ber and spacing to the stud bosses in the casting and xed to the secondsection, means for relatively moving the sections toward each other toextend the core pins through the first section into the mold cavity,means operable subsequent to the molding operation for moving the secondsection in a direction away from the rst section to withdraw the corepins from the casting,:

sleeves upon the core pins having the outer ends extending intothe firstsection for abutting ento eject the casting from the latter section.

6. Permanent molding apparatus for forming a cylinder head castinghaving a plurality of combustion chambers therein and having a series ofstud bosses, comprising permanent mold sections mounted for relativemovement toward each other and having portions on adjacent surfacesthereof cooperating vin the innermost positions of the same to form apermanent mold cavity, a member positioned adjacent the sectionsaforesaid and having a plurality of core pins corresponding in numberand spacing to the stud bosses in the cylinder head casting, means formoving said member to extend the core pins Ias a unit through one ofsaid sections into the mold cavity and for withdrawing the pins from themold cav-ity upon completion of the molding operation, means operable intimed relation to the Withdrawal of the core pins from the cavity7 toseparate the sections, and means engageable with the side face of thecasting contacting one mold section to clamp the opposite face of thecasting to the other section upon separation of the sections.

7. Permanent molding apparatus for forming a cylinder head castinghaving a plurality of combustion chambers therein and having a series ofstud bosses, comprising permanent mold sections mounted for relativemovement toward each other and having portions on adjacent surfacesthereof cooperating in the innermost positions of the same to form apermanent mold cavity, a member positioned adjacent the sectionsaforesaid and having a'plurality of core pins corresponding in numberand spacing to the stud bosses in the cylinder head casting, means formoving said member to extend the core pins as a unit through one of saidsections into the mold cavity and for withdrawing the pins from the moldcavity upon completion of the molding operation, means operable in timedrelation to the withdrawal of the core pins from the cavity to separatethe sections, means engageable with the side face of the castingcontacting one mold section to clamp the opposite face of the casting tothe other section upon separation of the sections, and means forsubsequently ejecting the casting from the last named permanent moldsection.

8. Molding apparatus for forming 4a casting having al predeterminedcontour comprising, a plurality of lrelatively movable permanent moldsections, one of said sections having mold forming portions on one facethereof cooperating with complementary mold forming portions on anadjacent face of another section in one relative position of thesections to form a mold cavity, a third section having a plurality ofpermanent core members thereon fashioned to extend into the mold cavitythrough aligned openings in one vof theaforesaid sections when thesections are in the above mentioned relative positions thereof, meansfor automatically eecting relative movements of the sections from theforegoing relative positions thereof in accordance with a predeter`mined sequence to open the mold, and means engageable. with one outerside face of the casting during relative movement of the sections toopen themold for clamping the opposite side face into engagement withthe adjacent mold section.

9. Molding apparatus for forming an engine cylinder head having studbolts openings therethrough, comprising a permanent mold section, a.metallic core member secured to one face of the section, a second moldsection cooperating with the permanent `mold section and core member toform Aa .cavity corresponding in contour to the cylinder head, core pinsextending into the cavity.

through aligned openings in the permanent mold section and core memberto form the stud bolt openings in the head, ejector sleeves luponthecore pins having the inner ends normally arranged to form the surfaceof the head surrounding the stud bolt openings, vand means forrelatively moving the permanent mold section and sleeves to extend theinner ends of the latter into the mold cavity.

CII

10. Molding apparatus for forming a castingl having a predeterminedcontour, comprising a plurality of relatively movable permanent moldsections cooperating in one relative position to form a mold cavitycorresponding in shape to the contour ofthe casting, means forrelatively moving the sections from the aforesaid position thereof toopen the mold, means extending through one section and engageabie withthe permanent mold, and means for relatively movface of the castingcontacting the latter section ing the latter section and ejector meansfor ejectto clamp the opposite tace of the casting to the ing thecasting from this section.

adjacent mold section upon relative movement 1 RANDOLPH J. ROSHIRT. ofthe sections to open the mold, ejector means ARTHUR T. BATEIMAN.associated with the last named section of the ANDREW IRVINE.

